You really want to fuck up an airport? Do the following, in no particular order.

1. Spoof GPS, as in emulate the constellation. Randomize it every few minutes. Move transmitter around.

2. Plain old jam GPS. You can buy cheap and nasty GPS jammers. If you're good with electronics, hook em up to a 555 timer and trigger to prevent a lock but like 5% duty cycle.

3. Spoof ADS-B to create thousands or 10's of thousands of planes in airspace. Most systems will die from not enough ram to handle these. If they do survive, then they'll get alerts from everything everywhere.

4. Jam ADS-B. Not as terrible, but still bad.

5. Build a Gnuradio flow that watches 117.975-137 MHz and selectively emits white noise on channels when in use. Kills comms.